Improving energy efficiency: a highly efficient coaxial design for a laser ranging system with a splicing lens.

Light detection and ranging (LiDAR) systems have made significant contributions in different applications. The laser ranging (LR) system is one of the core components of LiDARs. However, existing coaxial LR systems suffer from low energy efficiency due to obstruction of the reflection mirror. In this study, we carefully design a laser transmitter and receiver subsystem and consequently propose a highly energy-efficient coaxial design for a time of light-based LR system, where a perforated mirror and splicing lens account for the promotion of energy efficiency. The small hole in the perforated mirror is located on the object focus of the focusing lens to ensure the laser beam will pass through the perforated mirror without obstructions. The ring-shape splicing lens, consisting of two parts, is used for laser collimation and laser reception simultaneously. Laboratory experiments proved that the proposed design eliminates the complex calibration process for noncoaxial LR systems while reaching a comparable energy efficiency, which is higher than 98%. We believe it is an economical yet efficient way to promote the energy efficiency of coaxial LR systems.